@misc{10481/71344,
year = {2021},
month = {10},
url = {http://hdl.handle.net/10481/71344},
abstract = {The reinforcement function of shell ribs depends not only on their vaulted morphology but also on their
microstructure. They are part of the outer layer which, in the case of the Pinna nobilis bivalve, is built from almost
monocrystalline calcitic prisms, always oriented perpendicular to the growth surfaces. Originally, prisms and
their c-axes follow the radii of rib curvature, becoming oblique to the shell thickness direction. Later, prisms bend
to reach the nacre layer perpendicularly, but their c-axes retain the initial orientation. Calcite grains form
nonrandom boundaries. Most often, three twin disorientations arise, with two of them observed for the first time.
Nano-indentation and impact tests demonstrate that the oblique orientation of c-axes significantly improves the
hardness and fracture toughness of prisms. Moreover, compression tests reveal that the rib area achieves a unique
strength of 700 MPa. The detection of the specific microstructure formed to toughen the shell is novel.},
organization = {Polish National Agency for Academic Exchange (grant PPI/APM/
2018/1/00049/U/001)},
organization = {National Science Center (grant UMO-
2018/29/B/ST8/02200)},
organization = {European Social Fund (Project No.WNDPOWR.
03.02.00-00-I043/16)},
organization = {CGL2017-
85118-P of the Spanish Ministerio de Ciencia e Innovaci´on},
publisher = {Elsevier},
keywords = {Biogenic calcite},
keywords = {EBSD},
keywords = {Twinning},
keywords = {Mechanical anisotropy},
keywords = {Nano-indentation},
keywords = {Compressive strength},
title = {Ribs of Pinna nobilis shell induce unexpected microstructural changes that provide unique mechanical properties},
doi = {10.1016/j.msea.2021.142163},
author = {Nalepka, Kinga and Checa González, Antonio G.},
}